[ncmncm]

You read the article several times, yet didn't understand it.

As noted in the article, the Scottish play displays other oddities. But this one had not been commented upon before. To demonstrate vacuity, you would need to identify other plays that do not come off as creepy, but use "the" in the way noted. For an academic presentation, we might expect the authors to have checked for it in other plays, but this article was not.